<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Number数据类型</title>
</head>
<body>
<script>
    console.log(isNaN(10));  // false
    console.log(isNaN('10'));  // false
    console.log(isNaN(true));   // false
    console.log(isNaN('abc'));  // true
    console.log(isNaN(NaN));  // true
    console.log(isNaN(undefined));  // true
    console.log(isNaN(null));  // false
    console.log(null == 0);  // false
    console.log(undefined == 0);  // false
    console.log(undefined == false);  // false
    console.log(null == false);  // false

</script>
</body>
</html>